We got a bit obsessed with this DIY soda machine, which turns tap water into club soda without using electricity: It runs on CO2 canisters that you send back to the company when empty (they refill and reuse them). Once you’ve made the soda, add any flavoring you want. Ditch the syrups that come with the machine and make your own using juices, fruits, or herbs. (Check out plentymag.com for our homemade tonic recipe — a perfect complement to your fave eco-friendly vodka.)

This article originally appeared in Plenty in December 2006. This story was added to MNN.com in June 2009.